The operation of this kind of apparatus, intended for the operative connection between the folding system and the packaging system, is critical due to the difficulty of ensuring high working speed (in any case, required by the market) with light and foldable material normally being treated (tissue paper).
Known machines or apparatuses of this type can be found in what is disclosed for example in European patent EP537125 to the same present applicant. These machines comprise belt or chain conveyor systems that feed single folded article from the outlet of the folding machines towards an accumulation and counting unit having the function of grouping the articles in stacks, each including a pre-settable number of pieces, controllable as needed. The accumulation and counting unit comprises a series of adjacent and mutually spaced collecting discs (variable in number depending on the size of the machine), revolving in a mutually integral fashion and provided with pockets, for collecting single folded products, the pockets being in the shape of curvilinear tangential laminations, adjacent to one another and partially superimposed, in such a way that each pocket, indeed defined by the spacing between two consecutive laminations, is adapted to house a single folded article.
The articles are then extracted from the discs and are grouped in orderly stacks through devices that are driven in a suitable and synchronised manner with the rotation of the collecting discs, and cooperating with the latter so as to gradually accumulate a group or a stack of articles and to convey it towards conveyor systems that take the groups of formed articles and conduct them towards the packaging system.
As mentioned, the problems that affect known apparatuses essentially result from the difficulty of ensuring reliable performances in high-speed operation, as imposed by more and more demanding productive requirements. From this point of view, there is an ongoing active search for new and alternative solutions that best combine flexibility, speed, reliability (avoiding machine stopping time, product waste and malfunctioning of the packaging machines), as well as constructive simplicity.
Such solutions must integrate the system for collecting, counting and conveying the product from the folding machine in a flexible, reliable manner with very high productivity and without substantial speed limits.